Here’s my tale of woe…
My wife drives a '96 Olds Achieva. She complained that there was a grinding noise coming from the front end when she drove it. So, I took it out for a drive, and sure enough, I heard it. I parked the car in the driveway, and when I looked through the driver’s side wheel, I saw that the rotor was scarred pretty bad. I was surprised, since the brake pads weren’t that old – but I pulled the wheel off and found the brake pad material had fractured, causing the metal bracket part to gouge the rotor pretty awful. So, I set off to replace the brake pads and rotors on the whole front end.
No problem, the pads I’ve done many times before, and the rotors aren’t even clipped in – once you remove the caliper, they just pull off. When I got the driver’s side caliper off, though, I found the boot on the piston was cooked / ripped, and although there wasn’t a leak, I figured it was inevitable. No problem, I added a caliper to the shopping list. I picked up the parts and put them on, bled the caliper, reassembled everything, and took it out for a quick test / seating drive. It stopped just fine, no noises or shudders. The next day, we went on a 200 mile road trip. As we were driving, I noticed a bit of fade and uneven stopping. When we got there, there was an aweful smell coming from the wheel. I put my hand nearby the driver’s side front wheel, and it was extremely hot. I let it sit to the next day. I figured the new caliper must have stuck. There was light scoring on the outside edge only of the rotor. I decided to replace the new caliper. I borrowed tools and a vehicle from my wife’s aunt & uncle to get to the local parts place and did the swap. I thought the problems were over. I took it out for a test drive, and the wheel remained cool, problem solved(?)We drove the 200 miles back home without incident.
Fast forward a month of short trip driving, without comment. We take the car on a 100 mile trip, I’m driving. I notice a lot of wheel-synchronized noise coming from the front end. I stop at a gas station and notice the front driver’s side tire looks low, so I fill it up. At that time, I noticed nothing else unusual – so the wheel wasn’t noticably hot, or giving off a smell. We continue the drive, and it’s quieter. We get to our destination, and I notice the slightest of “cooked brake” smells, but it’s nearly midnight, and I have a lot to carry, so I don’t look into it. A few days later, we drive home, and when we get out (it’s dark out) I notice the smell again and the front driver’s side brake rotor is actually glowing a dull red. We decide it’s not a good idea to drive it anywhere else until we figure out what’s going on. A few days later, I pull the wheel, and look at the pads/rotor/caliper. Everything LOOKS OK. With the car up on a jack stand, I can move the rotor by hand, so it’s not significantly “stuck”. It doesn’t look gouged or grooved. There’s plenty of pad. I put the wheel back on and go for a short drive (~10 min). When I get out, the front driver’s side wheel is hot, but the passenger side is cool.
So… does anyone have any clue what is causing it to be so hot? Obviously, the pad is rubbing… but why? It’s the second caliper, is it that likely to be the problem? Could it be the rotor? I didn’t change that a second time. Is there anything else that could cause it to rub? Is it possible something (like hitting a big pothole?) could have bent something else and caused the whole caliper mount to be askew, and broken the original pad in the process? I can change the rotor / pads again, but am I wasting my time?
Here’s my tale of woe…
Are the guide pins clean, straight, and lubricated with the correct synthetic caliper grease? Are the rubber bushings in the caliper in good condition (not swollen)? Try mounting the caliper without the pads installed. Does it move freely (there will be a little resistance)? If the caliper is floating correctly, then I’d suspect a hydraulic problem, namely a bad flex line. A flexible brake line that appears fine on the outside can be damaged internally, and actually have a restriction in it. When you apply the brakes, you are generating enough hydraulic pressure to push the fluid through to the caliper, but the restriction doesn’t allow the pressure to bleed back up the system, and the caliper doesn’t release fully.
If you hit a pothole hard enough to damage the caliper mount, you’d have other carnage. I’d say extreme heat cracked the original pad.
Yep. Stronzo has it right. Replace the rubber brake hose. It could be a good idea to replace the rubber brake hose on the other side, also. It could fail next.
Three’s the charm. Most brake hoses are made out of fabric and sythetic rubber. A length of fabric can wear away from inside surface of hose, acting like a reed valve. W/caliper stuck on the rotor open the bleeder screw on the caliper. If caliper unsticks culpret is the hose.
Both times, I bought the caliper kit complete with new pins and bushings, already lubricated. They seemed to slide fine. I’ll try the flex line. Thanks!
And now that your brake fluid has been extremely hot a few times, you might as well flush that after you replace the brake hoses.